Wheat is one of the most important food crops in the world, and is a dominant grain of world commerce. As is well known in the art, the hardness of wheat grain varies between different wheat cultivars. Grain hardness refers to the texture of the kernel (caryopsis), in particular whether the endosperm is physically hard or soft. Grain texture, or “hardness”, influences processing, including e.g., milling, the characteristics of milled granular products of different wheat grain varieties, and how those varieties and granular products are used in foods.
Different grain textures are exploited to produce a wide variety of granular products including e.g., flours, semolinas, farinas, as well as a wide variety of food products. Generally speaking, hard wheat (Triticum aestivum) is used for bread and pasta, whereas soft wheat (T. aestivum) is used for cookies, cakes and pastries (Morris & Rose, Cereal Grain Quality, Chapman & Hall, New York, N.Y., pp. 3-54 (1996)). Typically, the very hard durum wheat (T. turgidum ssp. durum) is used in pasta, bread, couscous and bulgur.
Soft wheat typically produces a finer granulation upon milling or grinding, hard wheat a coarser granulation, and durum wheat a very coarse granulation. Although granulation is controlled somewhat by the art of milling, it is still highly limited by the inherent hardness characteristics of the wheat variety.
Durum wheat is universally recognized as the ideal raw material for the production of quality pasta products. In particular, durum wheat is high in protein and gluten, both of which are necessary components for pasta making. As noted above, durum wheat typically has a grain with a very hard textured endosperm. Consequently, it is typically milled into a granular meal of coarse particle size called semolina. Finer granulations can be produced however to produce a durum meal or flour of a particular granularity, more energy is required for milling than is required for the milling of other wheat having grain with softer textured endosperm. Thus, it is particularly difficult to obtain a finely granulated flour from durum wheat without incurring excessive starch damage and expending considerable energy. Yet, finer granulations are increasingly preferred by modern pasta manufacturers.
Starch damage influences water absorption and other dough properties, and despite other desirable factors e.g., protein content, pasta prepared with highly damaged starch is typically of inferior quality e.g., is sticky and has poor “mouth feel”, and is therefore considered by most people to be unacceptable. See e.g., Pasta and Noodle Technology James E. Kruger et al. eds., American Association of Cereal Chemists (1996).
Thus, the energy expended in milling the durum wheat kernels into semolina and flour must be carefully controlled so as to achieve the desired granulation with minimal starch damage. Therefore, to take full advantage of the beneficial and desirable characteristics of durum wheat, what is needed in the art is a durum wheat having grain with soft textured endosperm. Indeed, such a wheat cultivar would inter alia, produce soft textured wheat grain which could be ground into various granulations including finely textured flour without extensive amounts of starch damage an/or which could be ground more easily into semolina with much less energy expended.
Transgenic soft kernel wheat is known (see e.g., U.S. Pat. No. 6,596,930). However, there are barriers to widespread use of genetically modified cultivars. Indeed, genetically modified crops face high regulatory and research costs, and are opposed by many NGOs, and several governments, particularly within the European Community and Japan.
Therefore, a durum wheat having grain with soft textured endosperm that is also non-transgenic would meet the need for soft textured durum, and would also get around the barriers to widespread use that face genetically modified crops.
Fortunately, as will be clear from the following disclosure, the present invention provides for these and other needs.